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Thinking Like a Psychologist Part II Slide 2 Agenda Roll call Collect Essay #2 Discuss APA Mastery Test Discuss Term Paper Theories, Falsifiability, and More Plan for next week / Announcements Slide 3 3 Characteristics of Science Systematic Empiricism Making observations about the world in such a way that reveals something about how the world works. Replication and Peer Review (Public Knowledge) All scientific knowledge is to be shared with public (other scientists) for them to review its credibility and to attempt replication. Empirically Solvable Problems (Testable Theories) Psychologists only work to solve problems / answer questions that are answerable by empirical methods. Slide 4 Examples teach us what? Get into groups and discuss your assigned example. Be sure to discuss: The details / history of the example What principle the example illustrates Why its important to psychologists Example List: Little Green Men Birth controlling toasters Amazing Randi Goldberger Clever Hans & Facilitated Communication Slide 5 Theories & Hypotheses Theory An interrelated set of concepts that is used to explain a body of data and to make predictions about the result of future experiments (Stanovich, 2010, p. 21) A systematic and falsifiable explanation for observable events that is based on observable events. Theory vs. Guess? Falsifiability Hypothesis Specific predictions derived from theories (Stanovich, 2010, p. 21) Testable predictions. Slide 6 The Falsifiability Criterion What is falsifiability? A property of a scientific theory The theorys ability to be incorrect A theory or prediction that cannot be wrong is not falsifiable and therefore, not scientific Slide 7 Slide 8 Constructs, Concepts, and Reality Concept: an idea/phenomenon given a specific name and definitionoften lack strong empirical evidence for its existence. Construct: an idea/phenomenon or collection of related ideas/phenomena that are given a specific name and definition. Often has strong empirical evidence for its existence. All constructs must be operationalized to be of use to psychology. Slide 9 Essentialism The act or practice of trying to find the essence of something. What does it really mean to love? What is gravity, really? Concerned with ultimate definitions or essential properties. Not how science worksone CANNOT discover the essence of something through observation. Slide 10 Operationalism The act or practice of trying to define something by observation. Love is The relative degree of pupil dilation when the significant other enters the persons field of view An increased level of oxytocin present in the persons pre-frontal cortex Gravity is the force that causes all objects with mass to move toward each other. Concerned with observable definitions or empirical properties. Defining concepts using measurement. HOW SCIENCE WORKS we define our terms operationally Slide 11 Operational Definition Practice Lets try making some operational definitions of these constructs Anxiety Reading ability Good driving skills Depression Introversion Hunger Slide 12 Reliability and Validity Reliability: consistency over time or situations Test-retest reliability Inter-rater reliability Validity: accuracy of measurement (are you really measuring what you claim to be measuring and only the whole truth and nothing but the truth) Construct validity do the measures/treatments match the construct? Content validity does the measure represent all the facets of the construct? Best operational definitions are both reliable and valid. Slide 13 How to think straight about them Slide 14 Case Studies An in-depth study of one particular subject Gives a detailed portrayal of one persons experience The studys purpose is to present reality as it happens (whether good or bad) Subject to peer review and public scrutiny from the scientific world Useful for the early stages of investigation helps uncover variables, issues, etc. Slide 15 Testimonials An individuals personal experience to show support for a product, treatment, or truth. A person gives a detailed portrayal of his/her experience The persons purpose is to present reality as it happened (whether accurate or not) NOT subject to peer review and are often solicited from providers of product/treatment. Slide 16 Whats wrong with testimonials? Theres a testimonial for almost EVERY treatment, therapy, product, or service. If everything works, nothing works. Testimonials describe what worked for ONE person not what works for MOST people, or what WORKS BEST for most people. My Yugo lasted for 200K miles it was the best car I ever had! Placebo Effect The Vividness Problem Slide 17 Placebo Effect People get better without treatment/therapy They think theyre getting treatment In studies, it is necessary to compare results of treatment to placebo effect. (Without controlling for placebo effect, cant tell whether the thought of treatment or the actual treatment caused changes.) Slide 18 Vividness Problem A vivid example or case often carries more weight than a series of scientific studies. Repeat criminals an especially terrible crime by a repeat offender that gets lots of media attention will likely lead to new, tougher laws on 1st-time offenders (even if repeat offense rate is very low) Abduction vs. car accident Plane flight vs. car ride Testimonials are often vivid, moving accounts of an individuals experiencesthese tend to be persuasive (but are worthless to prove a claim). Slide 19 Psuedoscience Claims of truth and reality that claim to be rooted in science, but are NOT. Astrology Graphology Psychic Readings Biorythms Psychoanalysis Much of the self-help literature Misdirects, misinforms, misguides Is NOT Psychology Slide 20 A common misconception Slide 21 Relationship vs. Cause 2 things can be related WITHOUT one causing the other Shoe size and height Ice cream sales and crime rates SAT scores and college performance Synonyms for related X predicts Y X correlates with Y X varies with Y Individuals with high X have high Y (or low) Slide 22 Relationship vs. Cause Incorrect words when things are only related X causes Y X leads to Y X increases Y (misleading) When reading or conducting relational research, must be careful in interpreting results. NO CAUSAL INFERENCE ALLOWED. Slide 23 Correlational Research Studies whether 2 or more variables are related to each other. When one increases, does the other increase? When one increases, does the other decrease? When one increases, does the other stay flat? Things that are correlated: Job Satisfaction and Pay? Hours spent studying and score on final Toasters and pregnancy Cell-phone use and cancer (maybe) Slide 24 Correlations Problems When 2 variables are correlated, one cannot establish a causal link w/o more research. Correlation doesnt prove causality The 3 rd variable problem Goldberger eats S!-!|T Disease was correlated to poor sanitation Disease was correlated to poor nutrition Poor sanitation was correlated to poor nutrition The Directionality Problem One cannot determine, from correlation, which causes which. (self-esteem and academic performance) Slide 25 Control Necessary to make causal inferences and rule out alternative explanations When a researcher holds everything in 2 (or more) different situations constant except for a particular variable Requires that we separate and individually control variables that may naturally occur together Then if the outcome changes, the only explanation is the variable that changed Outcome = Dependent Variable Manipulated variable = Independent Variable Slide 26 Control (contd) VariablesQuiet ConditionNoisy Condition Noise Level (IV)LowHigh IQ (EV)Average Room Temperature (EV)7082 Sex of Subjects (EV)60% Female Task Difficulty (EV)Moderate Time of Day (EV)MorningAfternoon Slide 27 Control (contd) The Control Group A group of participants that receives no (or alternative) treatment Why important? Examples of importance Clever Hans Facilitated Communication Separation of Variables Must rule out alternative explanations; therefore must create artificial situations where variables that naturally occur together are teased apart. Slide 28 Slide 29 Research Methods There are 6 basic categories of scientific method that virtually all research falls into Research Non-ExperimentalExperimental Naturalistic ObservationQuasi-Experimental Survey Relational Research Field Study Experimental Slide 30 Research Methods Naturalistic Observation Addresses most basic scientific question: What is out there? Requires operational definition of events to be observed Observer must be unobtrusive, and design must be nonreactive Slide 31 Research Methods Field-Based Research Like naturalistic observation, conducted in real-world settings Goal is to establish natural relations among events Observer must be unobtrusive, but methods are intentionally reactive Slide 32 Research Methods Survey Research Appropriate to the study of private behaviors Two primary styles: Interviews (structured/unstructured) Questionnaires (structured/unstructured) Slide 33 Research Methods Relational (Correlational) Research Goal to verify systematic (usually linear) relations among events Strengths/directions of relations generally expressed in form of correlation coefficient (r xy ) Slide 34 Research Methods True Experiment Goal: to establish a cause-effect relationship among events Does low-fat diet cause decrease in cancer risk? Does exposure to violent video games cause increase in violent behaviors? Does spaced study cause increase in memory accuracy and retention? Do genetic variations cause sexual preference? Slide 35 Research Methods True Experiment Requires: random assignment of participants to at least two equivalent conditions manipulation of one factor (independent variable, or IV) in one condition (experimental), leaving it unchanged in other condition (control) measurement of one other factor in both conditions (factor called dependent variable, or DV; measurement instrument called dependent measure, or DM) Slide 36 Research Methods True Experiment Concludes: if groups are NOT equivalent with respect to DV, and if the difference between the groups is so big it probably did not happen by chance, then manipulation of the IV caused the difference in the DV Slide 37 Research Methods Quasi-Experiment Goal also to establish cause-effect relations among events Required when random assignment is not possible, because must use pre-existing groups, or IV impossible to manipulate directly, or IV unethical/illegal to manipulate directly Slide 38 Research Methods Review Name 6 categories of scientific research Which method of research can be used to establish cause and effect relationships?